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Glazed pads and/or bad vacuum booster are a red herring. You're not getting sufficient clamping which would lead me to think that the master isn't providing hydraulic pressure or something is preventing the caliper piston travel. Since ( or if) the car is not pulling to one side or the other I'm putting my money on the master. I would also recommend replacing the flex lines. They rot from the inside and could look just fine but be almost completely blocked...
 

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I am subscribed to this thread as I also have never been happy with the stopping power of my '91 Spider Veloce. While there are some who say they can lock up their brakes, and I totally believe them, I have never been able to.

I do not want to divert the OP journey but for me, I have:

Replaced the master cylinder (bench bled and pressure bled the brake lines)
Replaced the Booster
Replaced the flex lines to braided SS
Rebuilt the calipers
Replaced the pads

All of this and no difference.

The only things left for me to do is replace the Rotors and the hard lines.

I have driven another local Alfisti;s Spider, mcola, and it was the same.

I hope the OP finds something.

Good luck, I'm watching.

Vin
 

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Discussion Starter #43
Glazed pads and/or bad vacuum booster are a red herring. You're not getting sufficient clamping which would lead me to think that the master isn't providing hydraulic pressure or something is preventing the caliper piston travel. Since ( or if) the car is not pulling to one side or the other I'm putting my money on the master. I would also recommend replacing the flex lines. They rot from the inside and could look just fine but be almost completely blocked...
I'm in the process of replacing the rotors, wheel bearings, flex hoses, pads and caliper seals. Blew out the caliper hydraulic channels, and refurbished the glides on the calipers. So the only thing I didn't do that is on the list from those Alfisti suggestions above, is rebuild/replace the Master Cylinder and vacuum booster.
My testing suggests the booster is not the issue; so I'm going to pass on that for now. But I should probably rebuild the MC (bench bleed afterwards), since I'm going to need to bleed the whole system anyway.
Given I rebuilt the rear brakes last year, and I can't get them to skid either, the MC is a good suspect, I figure.
 

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You guys don't have ABS by any chance ... lol

Or do you need to do a few leg presses at the gym? ... hehe
Pete
 

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Push hard and live
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I wouldn’t bother rebuilding the MC. New ones are about $65. Not worth the time to rebuild.

Once it’s installed, we can discuss bleeding techniques.
 

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Discussion Starter #48
Well, finally got the flex lines replaced, calipers rebuilt and installed with new rotors, pads, wheel bearings. I’ll do the bleeding tomorrow, then a test drive and hope I get better clamping force.
 

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Good luck!

Vin
 

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Make sure you wear your safety belt, don't want you to face plant the steering wheel :)
Pete
 

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Well, finally got the flex lines replaced, calipers rebuilt and installed with new rotors, pads, wheel bearings. I’ll do the bleeding tomorrow, then a test drive and hope I get better clamping force.
Remember, you've got to properly bed the brakes: don't just take them out and start doing panic stops. There are various procedures for bedding them, or just drive the car without hard braking for a couple hundred miles.
 

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Discussion Starter #55
The front brakes are a lot better now. I can hold the car on my 25degree driveway. And can ALMOST lock them up.
After bleeding them, i notice bubbles come out if the MC in the the back half of brake reservoir whenever i pump the brakes. didn’t notice that before. I’ll do another bleeding on all four wheels, in order of rear passenger, front passenger, rear driver, front driver. Any other thoughts?
 

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On most Alfas, my method for bleeding involves several steps, and patience.

After assembling all the bits, I fill the reservoir. Install a hose on the left rear and right front bleed screws, crack them open slightly, and let them drip slowly into a jar. Go away for a day, but check that your reservoir doesn’t drain empty on either side.

Come back later that day, or the next. Using a pump oil can with a hose attached, pump fresh brake fluid UP from each wheel into the reservoir. I will sometimes have a willing assistant sit in the car and occasionally “tap” the brake pedal to dislodge bubbles trapped in the master cylinder. You will need to occasionally suck excess brake fluid out of the reservoir.

Generally, one or two iterations of this will get all the bubbles out. Bubbles want to go UP not DOWN.

On some peculiar master cylinders, I’ve had to resort to placing a hose on the right front and left rear bleed screws, crack them open, and put the ends of the tubes into a jar with brake fluid covering the end of the hose. It helps to use either speed-bleeder bleed screws, or coat the screws with something like thread-lube to prevent leakage or air ingress. Once this is set up, pump the brakes slowly, full stroke, with someone monitoring the reservoir to keep it full. This step can sometimes dislodge a bubble or two that the bottom-up method doesn’t get.
 

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By the way... resist fooling yourself. Alfa brakes CAN be locked up at high speed. If you can’t, you’re not done yet, or you should sign up at the local Crossfit gym.
 

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I didnt think i could lock up my brakes until one day I had an 18 wheeler stop short in front of me on the interstate...I learned my car will in fact lock up without issue with enough fear!!
Keep speed in mind when you test it out
 

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Yes, we are so used to modern cars with over servoed brakes that IMO caused accidents and required ABS to be invented.

Stupid engineering direction, removing a drivers ability to do their job well via feel.

I remember racing my Alfa Sud with standard inboard front brakes, but with racing brake pad compounds, and I was able to brake as late as the bravest, and you needed the full harness belt to keep you in the seat. Don't remember ever having to worry about lockups from 120+mph braking for a 2nd gear hairpin, but admittedly with sticky soft compound for racing tyres. Suds were cheaply made so a 105 series will do at least as well in this area.
Pete
 
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